JPH07308907A - Manufacture of pc product - Google Patents

Abstract

PURPOSE:To make the most of high productivity of an immediate form removal method and to dispense with a process of surface finishing of concrete after forming. CONSTITUTION:A double form composed of a main form 1 giving a mechanical strength as a form mainly and of an internal auxiliary form 2 fitted on the inside of the main form 1 and constituted of a sufficiently thin plate material is provided. Concrete 3a of a very small slump is placed in this double form and filled up therein by applying pressure and vibration thereto and a semi- finished product 3b covered with the internal auxiliary form 2 is removed from the main form before the concrete is set. After the semi-finished product 3b is cured properly, the internal auxiliary form is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently producing precast concrete (referred to as PC) products for various purposes, and particularly filling slump tiny concrete into a mold by applying pressure and vibration. And an improvement in a manufacturing method of a type that can be demolded almost immediately.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 1-15361 (B28B)
As disclosed in 1/8), in order to increase the production efficiency of PC products, the molding formwork is filled with zero-slump concrete, placed on a vibrating table, and the placing concrete is pressurized, Methods have been proposed for demolding almost immediately before curing.

[0003]

According to the above method, it is possible to obtain a concrete molded body (semi-finished product of PC) which does not lose its shape even if it is immediately removed from the mold. It was very difficult to prevent scratches and small defects on the surface of the semi-finished product because the surface of the product rubs against the mold. Therefore, conventionally, post-treatment has been performed to finish the surface of the semi-finished product immediately removed from the mold. In other words, plastering is applied to the concrete surface with cement etc. by means of iron, roller or spraying. After that, steam curing etc. are performed to complete the PC product.

In this way, if the surface finish of the semi-finished product is carried out as the post-treatment after demolding, the merit of the immediate demolding method of increasing the productivity of the PC product is significantly impaired, and the finished PC product is not processed. There is also a problem that the surface finishing layer easily separates from the concrete body over time.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to make use of the high productivity of the immediate demolding method and to eliminate the surface finishing step of the demolded semi-finished product. It is to provide a manufacturing method of.

[0006]

Therefore, in the present invention, first, a double formwork comprising a main formwork and an inner surface auxiliary formwork applied to the inner surface of the main formwork is provided. Then, concrete is poured into the double mold to apply pressure and vibration, and the semi-finished product covered with the inner surface auxiliary mold is demolded from the main mold before the concrete is hardened, After curing the semi-finished product, the inner surface auxiliary formwork was removed.

[0007]

The inner surface auxiliary form itself does not have mechanical strength as a form itself, and the main form is mainly responsible for the mechanical strength of the form when pouring and molding concrete. .
For example, concrete is placed in this double formwork to apply pressure and
Since the filling is performed by applying vibration, it is possible to obtain a concrete molded body (semi-finished product) that does not lose its shape even if the concrete does not harden. Therefore, the shape of this semi-finished product is sufficiently maintained even when the main formwork is demolded. Moreover, since only the main mold is removed from the inner surface auxiliary mold while covering the semi-finished product, there is no possibility that the surface of the semi-finished product is rubbed against the mold during demolding, resulting in scratches or defects.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, for example, a double mold as shown in FIG. This double formwork comprises a main formwork 1 mainly responsible for mechanical strength as a formwork, and an inner surface auxiliary formwork 2 made of a sufficiently thin plate material applied to the inner surface of the main formwork 1. . The main formwork 1 is made of metal or the like and is of a disassembly type, and the inner surface auxiliary formwork 2 is made of an inexpensive material such as a decorative plywood or a plastic panel. The inner surface auxiliary mold 2 is divided into several parts depending on the shape of the main mold 1, and is set to be attachable / detachable with respect to the inner surface of the main mold 1.

As shown in FIG. 1 (b), a very small concrete slump 3a is placed in the double formwork,
Vibration is applied to the entire formwork or concrete is pressed to densely fill the double formwork with concrete 3a. Since the slump of concrete is very small and is manufactured by pressurizing and vibrating, even if the concrete is demolded almost immediately after hardening before hardening, a concrete molded body that hardly deforms can be obtained.

However, in the present invention, as shown in FIG. 1 (c), only the main formwork 1 of the double formwork is demolded in the demolding process which is carried out immediately after the concrete is poured. The uncured concrete molded body 3b (semi-finished product) is in a state of being covered with the inner surface auxiliary mold 2. The inner surface auxiliary mold 2 is appropriately cured while being attached, and then the inner surface auxiliary mold 2 is also removed to obtain a completed PC product.

When the semi-finished product is removed from the main mold 1, another inner auxiliary mold 2 is set on the main mold 1 and
You can immediately proceed to the next concrete pouring process. In this way, the operating rate of the expensive main formwork 1 can be increased. When the semi-finished product is removed from the main formwork 1, the semi-finished product is covered with the inner surface auxiliary formwork 2, so that even if the semi-finished product is rubbed with the main formwork 1, the concrete surface is damaged or the concrete is damaged. There is nothing. Therefore, it is not necessary to finish for the purpose of repairing the surface of the PC product from which the inner surface auxiliary mold 2 has been removed.

[0012]

According to the present invention, the inner surface auxiliary formwork itself does not have mechanical strength as a formwork, and the mechanical strength of the formwork when pouring and molding concrete is the main formwork. The frame is mainly responsible. Since concrete is poured into this double mold and is filled by applying pressure and vibration, it is possible to obtain a concrete molded body (semi-finished product) that does not lose its shape even if the concrete is not hardened. Therefore, the shape of this semi-finished product is sufficiently maintained even when the main formwork is demolded. As a result, an expensive main formwork made of metal foam or the like can be operated with almost no dead time. Since the inner surface auxiliary formwork is attached to the semi-finished product even during curing, it cannot be operated without waste like the main formwork, but the inner surface auxiliary formwork can be made of inexpensive materials such as decorative plywood and plastic panels. ,No problem.

Also, since the inner surface auxiliary mold only demolds the main mold while covering the semi-finished product, the surface of the semi-finished product rubs against the mold at the time of demolding, causing scratches and defects. There is no fear. Therefore, it is not necessary to finish the surface of the semi-finished product by the plastering method as in the past, and the productivity as a whole is significantly improved. Of course, it is possible to avoid the problem that the surface finishing layer peels off with time as in the case of plastering.

[Brief description of drawings]

FIG. 1 is a schematic view showing a manufacturing process of a PC product according to an embodiment of the present invention.

[Explanation of symbols]

 1 Main formwork 2 Inner surface formwork 3a Casting concrete 3b Semi-finished product

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Miki Aoyama 4-640 Shimoseido, Kiyose-shi, Tokyo Inside Obayashi Technical Research Institute Co., Ltd. (72) Yoshimasa Hayashi 4-640 Shimoseido, Kiyose-shi, Tokyo Obayashi Engineering Co., Ltd. (72) Inventor Haruka Ogawa 4-640 Shimo-Seido, Kiyose-shi, Tokyo Inside Obayashi Technical Research Institute Co., Ltd. (72) Inventor Ibusa 4-640, Shimo-Seido, Kiyose-shi Tokyo Metropolitan Institute for Technical Research

Claims (1)

[Claims] 1. A double formwork comprising a main formwork and an inner surface auxiliary formwork applied to the inner surface of the main formwork, and concrete is placed in the double formwork to apply pressure and vibration. In addition, the semi-finished product covered with the inner surface auxiliary formwork is demolded from the main formwork before the concrete is hardened, and the inner surface auxiliary formwork is removed after curing the semi-finished product. PC product manufacturing method.